Advantages and Disadvantages of Oscilloscopes

An oscilloscope is a type of electrical measuring instrument with which you can analyze a signal's waveform. Unlike other types of measuring equipment, you can watch how a signal changes over time or in response to stimuli. Learn about the oscilloscope's advantages and disadvantages so that you know when the oscilloscope is appropriate for a given circumstance.

Close-up of a technician analysing an electrical device with an oscilloscope

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Real-Time Analysis

When you connect an oscilloscope's probe to a power source, the device immediately displays its waveform on the screen. The waveform is a visual representation of the signal's peaks and valleys. Other products, such as the multimeter, only display the voltage. By viewing the waveform in real time, you can quickly calculate its frequency, and watch for dips and spikes in the power source. This tool is important for diagnostic work, and not just to determine voltage or resistance.

Precision Control

There are many knobs and other types of controls on the face of an oscilloscope. With these knobs you can precisely control the size and shape of the waveform. With practice, you can locate and isolate other signals that may be interfering with the circuit that you are analyzing. For instance, you can use the "VOLTS/DIV" knob to increase the height of the waveform and get a better reading of its frequency. This knob is located on the left-hand side of most oscilloscopes.

Cost and Ease of Use

One disadvantage is that oscilloscopes cost many times more than other types of electronic measuring instruments, such as multimeters. They are also very sophisticated, and tend to be costly to repair if damaged. Additionally, you have to learn how to manipulate the oscilloscope's controls in order to get the best, highest fidelity signal from a circuit, which can take a lot of practice. This is in stark contrast to a device like a multimeter, in which you simply probe a circuit and see its voltage on the display instantaneously.

Signal Noise

Oscilloscopes can be overly sensitive to interference coming from nearby circuits. This is particularly true when using one to test a computer's electrical system. If you use it to test the motherboard, for instance, you receive some interference from the video card, the hard drive and even the computer's fan. You can filter this interference out if you have an expert knowledge of the oscilloscope's controls, but doing so still takes time.